Optical mark reading (OMR) systems are well known in the prior art and there are many applications for the use of OMR scannable forms in the largescale gathering of information (e.g. student test scores, census information, consumer preference surveys or product survey forms). The scannable forms for use in such systems are sheets of paper or other similar material that typically have a plurality of preprinted timing marks in a control mark column (often referred to as a timing track) and a plurality of response areas located on the sheet in a specified relationship with the timing marks. The timing marks are used to trigger the OMR system to scan or "read" the response bubbles that comprise a selected response area to detect whether a data mark is present at a particular response bubble.
OMR systems are well-suited for gathering information contained in a large number of documents with data that can be stated numerically or categorically (i.e., multiple choice, yes or no). In a typical market survey application, a person would fill in the requested information on a scannable form by placing a data mark in the desired response bubbles. When completed, the scannable form is then fed into an OMR scanner that reads the data marks and transmits this data to a computer for editing, validation, and, ultimately, interpretation. While such OMR systems are an efficient means of gathering large amounts of information, it is generally not cost-effective to use current scannable forms with an OMR system to gather relatively small amounts of information (i.e. 5,000 surveys or less), particularly when the turn-around time for conducting a survey is limited or when a scannable form must be custom-designed for a survey.
The scannable forms for OMR systems of the type described above are either fixed format scannable forms having only response areas and no corresponding questions printed on the form (e.g., 50 true/false response areas), or custom scannable forms with specific questions (or other stimulus items, such as graphics) printed corresponding to each response area (e.g., a census survey). Fixed format scannable forms are inexpensive, but are limited in arrangement and require another document or a survey administrator to pose the questions, because fixed format scannable forms do not combine both the question and response area on a single document. Custom scannable forms are more flexible in their format, but are expensive and may require as many as 5,000 copies of the same form to be printed before the costs involved in designing and printing the forms by conventional offset printing methods are recovered. More importantly, the time required to print customized scannable forms by conventional offset printing methods is sometimes too long (requiring one to eight weeks from initial design to final printing), and does not meet the market needs of many potential OMR users, particularly when there is a shortened time requirement, as is often the case in market survey applications.
One of the difficulties in creating a customized scannable form for use in current OMR scanners is the low tolerance such scanners have for offset, misregistration, and poor print or paper quality. In particular, the timing tracks on scannable forms for such scanners must be printed to high standards of print quality and print alignment to insure that an acceptable number of completed forms can later be properly scanned and scored. For example, photocopying a typical custom scannable form might produce scannable forms with a very low acceptance rate in current OMR scanners. This misalignment and poor print quality that causes such a low acceptance rate occurs because photocopy machines do not copy a page at exactly one hundred percent of its original size and because the alignment of the paper is not handled as precisely as in a conventional printing press. With the large costs involved in detecting and entering information from rejected forms, such a low acceptance rate is not tolerable in most OMR applications.
Similarly, customized survey forms created and printed by currently available laser printing using, for example, standard paint and draw software programs (e.g., MacDraw) will also have acceptance rates that are lower than desired. In particular, the print quality and alignment for the timing tracks required by current OMR scanners cannot be replicated by a laser printer for several reasons. First, current laser printers are not capable of printing along the edge of the form where the timing tracks for most OMR scanners are located. In addition, the print registration and image size required for the timing tracks is generally higher than can be obtained using a conventional laser printer. The paper handling mechanism in most laser printers varies from printer to printer and may be somewhat inconsistent in the alignment of the paper stock as it is fed through the laser printer. Finally, there is usually no means for accurately detecting the edge of the paper stock as it passes under the print head of a laser printer, causing the print area generated by the laser printer to "float" up and down from document to document.
A possible partial solution is the use of a blank scannable form having only a preprinted timing track as the paper stock for a laser printer. But the previously mentioned problems with alignment and consistency mean that there is still no way of establishing accurate alignment between the preprinted timing track on such a form and the corresponding rows of response bubbles to be printed by the laser printer. Current OMR scanners use the timing marks in the timing track to trigger when to scan the corresponding row of response bubbles in the response area. Consequently, if the response bubbles are not printed in relatively exact alignment with the corresponding timing mark, the OMR scanner may interpret the edge of a response bubble as a positive response or mark, rather than as a guide for the user filling in the data mark. Without a method of aligning the response bubbles with the corresponding timing marks, the resulting customized survey forms will not be consistently and correctly scanned by current OMR scanners.
Although the existing OMR scanners and scannable forms may be satisfactory for other uses and applications, because of the problems recited above they are not well-suited for quickly gathering information from a relatively small sample population by means of a customized scannable form. Accordingly, there is a continuing need of improvements in scannable forms for OMR systems to allow for the timely and cost-effective creation of customized scannable forms or survey forms that will be consistently and correctly scanned by current OMR systems.